Name the most common practice of recharging ground water.

What is the main purpose of rainwater harvesting ?

What is the name of the process in which rain water falling on the earth is stopped from flowing and made to percolate into the ground ?

The pH of a river water sample as measured by pH paper is found to be What does it tell us about water?

Name the person who is most remembered for the protection of Khejri trees in Rajasthan.